Stage 3: Leia and Chewbacca Help No One
Here is where the plan takes an unexpected turn. Leia disguised as a bounty hunter rolls into Jabbas place with Chewbacca as a pretend hostage for sale. Han Solo's loyal friend, is of course another prize in Jabbas eyes no doubt. With no mention of Han Solo within the heated negotiation, Leia threatens to blow Jabba up with a thermal detonator unless he pays the right price for Chewie. Jabba likes the balls that this bounty hunter scum shows, agreeing to her terms and taking Chewbacca in as a prisoner.
So Why Are Leia And Chewbacca Actually There?: This is where everything starts to contradict. Leias involvement here could very well have gotten Chewie killed. Also if shes just trying to get pally with Jabba and work her way undercover within the gangster's palace so that she can save Han herself, that undermines everything Lando has been doing there as its essentially the same play. You could argue that Leia is working alone in a plan to save her love interest Han Solo and her showing up at Jabbas palace is a fly in the ointment to Luke and even Lando's own plans. Its hard to tell from what we see in Return of the Jedi but in deleted scenes the Millennium Falcon is parked up with Lukes X-Wing on Tatooine, which implies they all arrived together as part of the grand plan. Maybe Leia and Chewies part is to just get inside the palace, awaiting Lukes arrival later on but even that doesn't make the plan any better really. Whatever Leias part in all this is, it doesnt pan out. She sneaks in to get Han out of carbonite (something you would assume Lando could have done many a time up to this point). She gets caught and gets Han thrown in a cell with Chewie (something no one could ever have predicted happening) and in turn Leia ends up as Jabbas new slave girl. Basically Leias moves, whether planned as a group of just her working alone really could have wound up with Han, Chewie and herself dead and all this before Luke even steps through the palace doors.